Tools/TestWebKitAPI/Tests/WTF/HashMap.cpp

/*
 * Copyright (C) 2011 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions
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#include "config.h"

#include <wtf/HashMap.h>

namespace TestWebKitAPI {

typedef WTF::HashMap<int, int> IntHashMap;

TEST(WTF, HashTableIteratorComparison)
{
    IntHashMap map;
    map.add(1, 2);
    ASSERT_TRUE(map.begin() != map.end());
    ASSERT_FALSE(map.begin() == map.end());

    IntHashMap::const_iterator begin = map.begin();
    ASSERT_TRUE(begin == map.begin());
    ASSERT_TRUE(map.begin() == begin);
    ASSERT_TRUE(begin != map.end());
    ASSERT_TRUE(map.end() != begin);
    ASSERT_FALSE(begin != map.begin());
    ASSERT_FALSE(map.begin() != begin);
    ASSERT_FALSE(begin == map.end());
    ASSERT_FALSE(map.end() == begin);
}

struct TestDoubleHashTraits : HashTraits<double> {
    static const int minimumTableSize = 8;
};

typedef HashMap<double, int64_t, DefaultHash<double>::Hash, TestDoubleHashTraits> DoubleHashMap;

static int bucketForKey(double key)
{
    return DefaultHash<double>::Hash::hash(key) & (TestDoubleHashTraits::minimumTableSize - 1);
}

TEST(WTF, DoubleHashCollisions)
{
    // The "clobber" key here is one that ends up stealing the bucket that the -0 key
    // originally wants to be in. This makes the 0 and -0 keys collide and the test then
    // fails unless the FloatHash::equals() implementation can distinguish them.
    const double clobberKey = 6;
    const double zeroKey = 0;
    const double negativeZeroKey = -zeroKey;

    DoubleHashMap map;

    map.add(clobberKey, 1);
    map.add(zeroKey, 2);
    map.add(negativeZeroKey, 3);

    ASSERT_EQ(bucketForKey(clobberKey), bucketForKey(negativeZeroKey));
    ASSERT_EQ(map.get(clobberKey), 1);
    ASSERT_EQ(map.get(zeroKey), 2);
    ASSERT_EQ(map.get(negativeZeroKey), 3);
}

} // namespace TestWebKitAPI